Cannabis, more commonly known as marijuana, is a genus of flowering plants that includes at least three species: cannabis sativa, cannabis indica, and cannabis ruderalis as determined by plant phenotypes and secondary metabolite profiles.
The use of cannabis for social and medical purposes has been known for almost of all humanity's recorded history. Cannabis is most commonly administered via inhalation or consumption of marijuana-infused food and drink. However, since 1972 marijuana has been classified as a Schedule I drug under the U.S. Controlled Substances Act because the U.S. federal government considers it to have “no accepted medical use.” In stark contrast to this position, a number of U.S. states and the District of Columbia have recognized the medical benefits of cannabis and have decriminalized its medical use.
In 2014, the U.S. Attorney General Eric Holder announced that the federal government would allow states to create a regime that would regulate and implement the legalization of cannabis, including loosening banking restrictions for cannabis dispensaries and growers.
The U.S. government has set a precedent for patenting cannabis, and cannabis-related inventions. For example, U.S. Pat. No. 6,630,507 issued on Oct. 7, 2003 and assigned on the patent face to The United States of America, is directed to methods of treating diseases caused by oxidative stress by administering therapeutically effective amounts of a cannabidiol (CBD) cannabinoid from cannabis that has substantially no binding to the N-methyl-D-aspartate (NMDA) receptor, wherein the CBD acts as an antioxidant and neuroprotectant. A search of the USPTO Patent Application Information Retrieval (PAIR) system reveals the existence of thousands of cannabis related applications and issued patents.
Despite the official position of the U.S. federal government, and as recognized by the states that have legalized it, cannabis has been shown to provide substantial benefits for medical and recreational uses. Cannabis is regularly used by a wide cross-section of society to treat a variety of maladies, conditions and symptoms including, but not limited to: nausea, glaucoma, lack of appetite, mucous membrane inflammation, epilepsy, leprosy, fever, obesity, asthma, urinary tract infections, coughing, anorexia associated with weight loss in AIDS patients, pain, and multiple sclerosis.
Cannabinoids are terpenophenolic compounds found in cannabis sativa, an annual plant belonging to the cannabaceae family. The plant contains more than 400 chemicals and approximately 70 cannabinoids. The latter accumulate mainly in the glandular trichomes. The most active of the naturally occurring cannabinoids is tetrahydrocannabinol (THC), which is used for treating a wide range of the aforementioned medical conditions.
Cannabidiol (CBD), an isomer of THC, is a potent antioxidant and anti-inflammatory compound known to provide protection against acute and chronic neuro-degeneration; cannabigerol (CBG), found in high concentrations in hemp, which acts as a high affinity; and cannabichromene (CBC), which possesses anti-inflammatory, anti-fungal and anti-viral properties. Many phytocannabinoids have therapeutic potential in a variety of diseases and may play a relevant role in plant defense as well as in pharmacology. Accordingly, biotechnological production of cannabinoids and cannabinoid-like compounds with therapeutic properties is of utmost importance. Thus, cannabinoids are considered to be promising agents for their beneficial effects in the treatment of various diseases.
One method of cannabinoid preservation includes separating a cannabinoid ethanol (EtOH) mixture from a cannabis extract through a filtration process, forming a slurry by combining a crystalline compound with the cannabinoid EtOH mixture, and heating and agitating the slurry in a pressurized chamber to form a colloidal cannabinoid EtOH mixture.
The colloidal cannabinoid EtOH mixture is distributed into a tray to form an evenly distributed mixture layer. An evaporation vessel is formed for the evenly distributed mixture layer through the attachment of a detachable cover to the tray, and the evaporation vessel is positioned and heated within a heating chamber. A rapid cooling process is performed as the evenly distributed mixture layer approaches saturation temperature, and this process is repeated until crystal formation is detected within the evenly distributed mixture layer. The evaporation vessel is removed from the heating chamber upon detection of crystal formation.
Recrystallizations of cannabinoids from solvents, in particular from non-polar hydrocarbon solvents, are well known in the art. These processes represent a classic recrystallization, where the solvent is heated to increase solubility of the compound to be recrystallized and then cooled, creating a supersaturated solution that grows crystals.
Other recrystallization processes include using a second, weak solvent that, when added to the saturated solvent, causes precipitation of crystals. Still other, less common recrystallization techniques exist for specialized crystal growth, such as those made for protein crystallography where a reactant is added to the solvent, producing a compound as it crystallizes.
In all cases, crystal growth is limited by the ability of the molecule to move into regularly ordered, crystalline structures while excluding impurities, without re-dissolving the growing crystals. If heat is applied, the solubility of the compound increases in the solvent and crystallization is limited. Kinetic energy as vibration can be applied, short of heating the solution, to provide kinetic energy for mass transfer without heat. Electrical potentials have been applied to crystal growth, enhancing the process under controlled conditions.
These processes rely on successive recrystallization passes that break down or destroy the previous crystal, release included impurities, and grow a new crystal that is more pure due to dilution of impurities in the solvent during the destruction phase. Crystal manufacturing processes prefer growing by deposition of new material, not purification by rearrangement because their process involves growth, destruction and regrowth. Time for growth has been the limiting factor in performing the recrystallization methods.
Conventionally, crystals and terpenes are not separated, as manufacturers typically are not concerned about having solvent left over after a purification process. Grams of crystals are produced from a mason jar, each gram appearing and being different from one another. The inventors have found, however, that separating, weighing, and then recombining the crystals and terpenes results in each crystal being substantially identical to each other.